58同城网站建设思路,免费自助网站,包装设计公司商业模式,wordpress 获取模板路径/*** author#xff1a;cp* time#xff1a;2021-2-24* Description: java死锁测试* 进程id查看命令#xff1a;jsp 找到对应的进程id* 通过jstack 进程id 输出死锁信息** 如何定位死循环导致的其他线程阻塞等待#xff1a;* linux下top命令查看cpu使用率较高的java进程authorcp* time2021-2-24* Description: java死锁测试* 进程id查看命令jsp 找到对应的进程id* 通过jstack 进程id 输出死锁信息** 如何定位死循环导致的其他线程阻塞等待* linux下top命令查看cpu使用率较高的java进程进而用top -Hp ➕pid查看该java进程下cpu使用率较高的线程。再用jstack命令查看线程具体调用情况排查问题。*/
public class DeadLockSample extends Thread {private String first;private String second;public DeadLockSample(String name, String first, String second) {super(name);this.first first;this.second second;}public void run() {synchronized (first) {System.out.println(this.getName() obtained: first);try {Thread.sleep(1000L);synchronized (second) {System.out.println(this.getName() obtained: second);}} catch (InterruptedException e) {// Do nothing}}}//死锁/*public static void main(String[] args) throws InterruptedException {String lockA lockA;String lockB lockB;DeadLockSample t1 new DeadLockSample(Thread1, lockA, lockB);DeadLockSample t2 new DeadLockSample(Thread2, lockB, lockA);t1.start();t2.start();t1.join();t2.join();}*/public static void main(String[] args) throws InterruptedException {ThreadMXBean mbean ManagementFactory.getThreadMXBean();Runnable dlCheck new Runnable() {Overridepublic void run() {long[] threadIds mbean.findDeadlockedThreads();if (threadIds ! null) {ThreadInfo[] threadInfos mbean.getThreadInfo(threadIds);System.out.println(Detected deadlock threads:);for (ThreadInfo threadInfo : threadInfos) {System.out.println(threadInfo.getThreadName());}}}};ScheduledExecutorService scheduler Executors.newScheduledThreadPool(1);// 稍等5秒然后每10秒进行一次死锁扫描scheduler.scheduleAtFixedRate(dlCheck, 5L, 10L, TimeUnit.SECONDS);//死锁代码String lockA lockA;String lockB lockB;DeadLockSample t1 new DeadLockSample(Thread1, lockA, lockB);DeadLockSample t2 new DeadLockSample(Thread2, lockB, lockA);t1.start();t2.start();t1.join();t2.join();}
}
上述代码示例会产生死锁 总结
1、进程id查看命令jsp 找到对应的进程id
* 通过jstack 进程id 输出死锁信息
2、如何定位死循环导致的其他线程阻塞等待
* linux下top命令查看cpu使用率较高的java进程进而用top -Hp ➕pid查看该java进程下cpu使用率较高的线程。再用jstack命令查看线程具体调用情况排查问题。
